The present invention relates to a hair dye composition having markedly high dyeing power, can strongly impart the hair with an extremely vivid red color, has less color fade over time and undergoes a small change in the color tone of the dye even after storage.
Hair dyes can be classified by the dye to be used therefor, or whether they have bleaching action of melanin or not. Typical examples include a two-part permanent hair dye composed of a first part containing an alkali agent, an oxidation dye and a direct dye such as nitro dye and a second part containing an oxidizing agent; and one-part semi-permanent hair dye containing an organic acid or an alkali agent, and a direct dye such as acid dye, basic dye or nitro dye.
The above-described permanent hair dye is however accompanied with the drawbacks that color tone imparted by an oxidation dye is not so vivid and the color of the hair dyed with a vivid-color producing nitro dye ordinarily employed as a direct dye markedly fades over time and becomes dull soon even if the color tone rightly after dyeing is very vivid (Japanese Patent Application Laid-Open (Kokai) No. Hei 6-271435).
Recently, hair dyes containing as a direct dye a so-called cationic dye having a cation group contained in their conjugate system have been reported (Japanese Language Laid-Open Publication (PCT) No. Hei 8-507545, 8-501322 or 10-502946, or Japanese Patent Application Laid-Open (Kokai) No. Hei 10-194942). They have been found to involve drawbacks that intended dyeing effects are not available owing to decomposition of them caused by mixing, upon hair dyeing, with hydrogen peroxide ordinarily employed as an oxidizing agent; and that when the cationic group is contained in an azo-based (xe2x80x94Nxe2x95x90Nxe2x80x94) conjugated system, they are unstable to an alkali agent or a reducing agent essentially contained in a permanent hair dye.
An object of the present invention is to provide a hair dye composition which has high hair dyeing power, less color fade over time, and excellent storage stability to permit only a small change in color tone of the dye after storage.
The present inventors have found that when the below-described compound which is known, in Offenlegungsschrift DE-3531774, as a cationic dye for dyeing or printing therewith fiber materials, paper or leather, is used as a hair dye, the resulting hair dye composition can strongly impart the hair with an extremely vivid red color without decomposing the dye upon hair dyeing, exhibits excellent light resistance, washing resistance, perspiration resistance, friction resistance and heat resistance, and undergoes a small change in the color tone of the dye after storage as compared with that rightly after preparation because the dye exists in the composition stably.
In one aspect of the present invention, there is thus provided a hair dye composition comprising, as a direct dye, a compound represented by the following formula (1): 
wherein, R1, R2, R3 and R4 each independently represents a C1-6 alkyl group which may have a substituent, an alkenyl group which may have a substituent or an aryl group which may have a substituent, or R3 and R4, when taken together with the adjacent carbon atom, form a 5- to 12-membered ring,
R5 represents a hydrogen atom, a C1-6 alkyl group which may have a substituent, an alkenyl group which may have a substituent, an aryl group which may have a substituent, or an acyl group,
X1 and X2 each independently represents a hydrogen atom or a halogen atom,
Y1 and Y2 each independently represents a hydrogen atom, a C1-6 alkyl group which may have a substituent, an alkenyl group which may have a substituent, a C1-6 alkoxy group which may have a substituent or a halogen atom,
Z1 and Z2 represents a hydrogen atom, a C1-6 alkyl group which may have a substituent, an alkenyl group which may have a substituent, a C1-6 alkoxy group which may have a substituent, a nitro group or a halogen atom, and
Axe2x88x92 represents an anion.
In another aspect of the present invention, there is also provided a method for dyeing the hair with the above-described hair dye composition.
In the formula (1), examples of the C1-6 alkyl group represented by R1, R2, R3 , R4, R5 , Y1, Y2, Z1 or Z2 include methyl, ethyl, propyl, isopropyl and cyclohexyl groups, each of which may be substituted by an aryl group, alkoxy group, amino group, mono-or di-(C1-4 alkyl)-substituted amino group, tri(C1-4 alkyl)-substituted ammoniumyl group, acyl group, hydroxy group, cyano group or halogen atom.
Examples of the C1-6 alkoxy group represented by Y1, Y2, Z1 or Z2 include methoxy, ethoxy, propoxy and isopropoxy and groups, each of which may be substituted by an aryl group, alkoxy group, amino group, mono- or di-(C1-4 alkyl)-substituted amino group, tri(C1-4 alkyl)-substituted ammoniumyl group, acyl group, hydroxy group, cyano group or halogen atom.
Examples of the alkenyl group represented by R1, R2, R3, R4, R5, Y1, Y2, Z1 or Z2 include vinyl and allyl groups, each of which may be substituted by an aryl group, an alkoxy group, amino group, mono- or di-(C1-4 alkyl)-substituted amino group, tri(C1-4 alkyl)-substituted ammoniumyl group, acyl group, hydroxy group, cyano group or halogen atom.
Examples of the aryl group represented by R1, R2, R3, R4 or R5 include phenyl and naphthyl groups, each of which may be substituted by an alkyl group, aryl group, alkoxy group, amino group, hydroxy group, cyano group, nitro group, trifluoromethyl group or halogen atom, more specifically, methyl group, ethyl group, methoxy group, ethoxy group, chlorine atom or bromine atom.
Examples of the 5- to 12-membered ring formed by R3 and R4 when they are taken together with the adjacent carbon atom include cyclopentane and cyclohexane rings.
Examples of the anion represented by Axe2x88x92 in the formula (1) include chloride ions, bromide ions, iodide ions, trichlorozincic acid ions, tetrachlorozincic acid ions, sulfuric acid ions, hydrosulfuric acid ions, methyl sulfate ions, phosphoric acid ions, formic acid ions and acetic acid ions.
Specific examples of the direct dye (1) to be used in the present invention. 
As a direct dye, at least one of these direct dyes (1) can be used or another direct dye can be used in combination therewith. In particular, combination with yellow and blue dyes makes it possible to dye the hair with a deep and highly lustrous dark brown or black color.
Examples of the direct dye other than the direct dyes (1) include Basic Blue 7 (C.I. 42595), Basic Blue 26 (C.I. 44045), Basic Blue 99 (C.I. 56059), Basic Violet 10 (C.I. 45170), Basic Violet 14 (C.I. 42515), Basic Brown 16 (C.I. 12250), Basic Brown 17 (C.I. 12251), Basic Red 2 (C.I. 50240), Basic Red 22 (C.I. 11055), Basic Red 76 (C.I. 12245), Basic Red 118 (C.I. 12251:1) and Basic Yellow 57 (C.I. 12719); and basic dyes as described in Japanese Patent Publication No. Sho 58-2204, Japanese Patent Application Laid-Open No. Hei 9-118832, Japanese Language Laid-Open Publication (PCT) No. Hei 8-501322 or Japanese Language Laid-Open Publication (PCT) No. Hei 8-507545.
The direct dye (1) is preferably added in an amount of 0.01 to 20 wt. %, more preferably 0.05 to 10 wt. %, especially 0.1 to 5 wt. % based on the whole composition (after mixture of all the component parts when the hair dye composition is a two part or three part type; this will apply equally hereinafter). When another direct dye is added in combination, the content of it in total with the direct dye (1) preferably ranges from 0.05 to 10 wt. %, especially 0.1 to 5 wt. %.
The hair dye composition of the present invention is preferably adjusted to pH 6 to 11, with pH 8 to 11 being especially preferred. Examples of the alkali agent to be used for pH adjustment include ordinarily employed ones such as ammonia, organic amines and salts thereof. The alkali agent is preferably added in an amount of 0.01 to 20 wt. %, more preferably 0.1 to 10 wt. %, especially 0.5 to 5 wt. % based on the whole composition.
In the hair dye composition of the present invention, an oxidizing agent can be incorporated. In this case, hair dyeing and bleaching can be carried out simultaneously, which facilitates more vivid hair dyeing. Ordinarily employed oxidizing agents, for example, hydrogen peroxide, persulfates such as ammonium persulfate, potassium persulfate and sodium persulfate, perborates such as sodium perborate, percarbonates such as sodium percarbonate and bromates such as sodium bromate and potassium bromate are usable. Out of them, hydrogen peroxide is especially preferred. The oxidizing agent is added in an amount of 0.5 to 10 wt. %, especially 1 to 8 wt. %, based on the whole composition.
In the hair dye composition of the present invention, an oxidation dye can be incorporated further. This incorporation enables markedly vivid dyeing not attainable by the single use of an oxidation dye. In this case, the above-exemplified oxidizing agents can be used as an oxidizing agent, with hydrogen peroxide being particularly preferred. Alternatively, an oxidizing enzyme such as laccase can be employed. For the oxidation dye, known color developers and couplers ordinarily employed for an oxidation type hair dye can be used.
Examples of the developer include p-phenylenediamines having one or several groups selected from groups NH2-, NHR- and NR2- (in which R represents a C1-4 alkyl group or a hydroxyalkyl group) such as p-phenylenediamine, p-toluylenediamine, N-methyl-p-phenylenediamine, chloro-p-phenylenediamine, 2-(2xe2x80x2-hydroxyethylamino)-5-aminotoluene, N,N-bis-(2-hydroxyethyl)-p-phenylenediamine, 2-hydroxyethyl-p-phenylenediamine, 2,6-dimethyl-p-phenylenediamine, methoxy-p-phenylenediamine, 2,6-dichloro-p-phenylenediamine, 2-chloro-6-methyl-p-phenylenediamine, 6-methoxy-3-methyl-p-phenylenediamine, 2,5-diaminoanisole, N-(2-hydroxypropyl)-p-phenylenediamine and N-2-methoxyethyl-p-phenylenediamine; 2,5-diaminopyridine derivatives and 4,5-diaminopyrazole derivatives, p-aminophenols such as p-aminophenol, 2-methyl-4-aminophenol, N-methyl-p-aminophenol, 3-methyl-4-aminophenol, 2,6-dimethyl-4-aminophenol, 3,5-dimethyl-4-aminophenol, 2,3-dimethyl-4-aminophenol and 2,5-dimethyl-4-aminophenol; o-aminophenols, o-phenylenediamines, 4,4xe2x80x2-diaminophenylamine and hydroxypropylbis(N-hydroxyethyl-p-phenylenediamine); and salts thereof.
Examples of the coupler include 1-naphthol, 1,5-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 5-amino-2-methylphenol, 5-(2xe2x80x2-hydroxyethylamino)-2-methylphenol, 2,4-diaminoanisole, m-toluylenediamine, resorcin, m-phenylenediamine, m-aminophenol, 4-chlororesorcin, 2-methylresorcin, 2,4-diaminophenoxyethanol, 2,6-diaminopyridine, 2-amino-3-hydroxypyridine, 4-hydroxyindole, 6-hydroxyindole, 2,4-diamino-6-hydroxypyrimidine, 2,4,6-triaminopyrimidine, 2-amino-4,6-dihydroxypyrimidine, 4-amino-2,6-dihydroxypyrimidine, 4,6-diamino-2-hydroxypyrimidine and 1,3-bis(2,4-diaminophenoxy)propane; and salts thereof.
As each of a developer and a coupler, at least one of the above-exemplified ones can be used. Although no particular limitation is imposed on the content of each of them, it is added in an amount of 0.01 to 20 wt. %, especially 0.5 to 10 wt. % based on the whole composition.
To the hair dye composition of the present invention, a known autoxidation dye typified by an indole or an indoline, or a known direct dye such as a nitro dye or a disperse dye can also be added.
When an anionic component (such as anionic surfactant or anionic polymer) is added to the hair dye composition of the present invention, it is preferred to satisfy the following equation:
xe2x80x9cIon activity concentration of the anionic component/ion activity concentration of the cationic direct dye (1)xe2x89xa68 xe2x80x9d
The term xe2x80x9cion activity concentrationxe2x80x9d as used herein means xe2x80x9cmolar concentration xc3x97ionic valencexe2x80x9d.
Addition of a polyol, polyol alkyl ether, cationic or amphoteric polymer or silicone to the hair dye composition of the present invention is preferred, because the resulting composition can dye the hair uniformly and has improved cosmetic effects of the hair.
In addition to the above-described components, those ordinarily employed as a raw material for cosmetics can be added to the hair dye composition of the present invention. Examples of such an optional component include hydrocarbons, animal or vegetable fats and oils, higher fatty acids, organic solvents, penetration promoters, cationic surfactants, natural or synthetic polymers, higher alcohols, ethers, amphoteric surfactants, nonionic surfactants, protein derivatives, amino acids, antiseptics, chelating agents, stabilizing agents, antioxidants, plant extracts, crude drug extracts, vitamins, colorants, perfumes and ultraviolet absorbers.
The hair dye composition of the present invention can be prepared in a conventional manner into a one-part composition, a two-part composition having a first component part containing an alkali agent and a second component part containing an oxidizing agent, or a three-part composition having, in addition to these two component parts, a powdery oxidizing agent such as persulfate. The direct dye (1) can be incorporated in either one or both of these component parts of the two-part or three-part composition. When the hair dye composition of the present invention is one-part type, it is applied to the hair directly, while the two- or three-part type is applied to the hair after mixing these parts upon hair dyeing.
No particular limitation is imposed on the form of the hair dye composition of the present invention. Examples include powder, transparent liquid, emulsion, cream, gel, paste, aerosol, and aerosol foam. It preferably has a viscosity of 2000 to 100000 mPaxc2x7s in the stage of application to the hair (after mixing of all the components when the hair dye composition is a two-part or three-part type).